The Vega specification consists of high level attributes such as scales, marks, axes, legends, etc, each with an array containing any number of individual marks, scales, etc. It’s useful to be able to index these arrays by name, so Vincent has introduced a Python List that can also be
indexed by a name parameter.

This indexing structure allows for faceting on col or idx for charts like stacked or grouped bars.

The best way to get data into Vincent is with the Pandas Series and DataFrame. These provide built-in indexing and index sorting, and will generally make your charts appear nicer. We’ll start with Series: